<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Sparkline Graphs GoJS Sample</title>
<meta name="description" content="Sparkline charts in a Diagram." />
<!-- Copyright 1998-2019 by Northwoods Software Corporation. -->
<meta charset="UTF-8">
<script src="../release/go.js"></script>
<script src="../assets/js/goSamples.js"></script>  <!-- this is only for the GoJS Samples framework -->
<script id="code">
  function init() {
    if (window.goSamples) goSamples();  // init for these samples -- you don't need to call this

    var $ = go.GraphObject.make;  // for conciseness in defining templates

    myDiagram = $(go.Diagram, "myDiagramDiv",  // create a Diagram for the DIV HTML element
                  {
                    layout: $(go.GridLayout, { wrappingColumn: 2, isOngoing: false }),
                    initialContentAlignment: go.Spot.Center,  // center the content
                    "undoManager.isEnabled": true  // enable undo & redo
                  });

    var SPARK_STROKEWIDTH = 1;
    var SPARK_INTERVAL = 3;
    var BASELINE_LENGTH = 75;

    function makeStringFromValues(values) {
      if (values.length < 1) return "M 0 " + values + " L " + BASELINE_LENGTH + " 0";
      // if only one value, make a line BASELINE_LENGTHpx long at that value
      var str = "M 0 " + Math.round(-values[0] * SPARK_INTERVAL);
      if (values.length < 2) str += " L " + BASELINE_LENGTH * SPARK_INTERVAL + " " + Math.round(-values[0] * SPARK_INTERVAL);


      for (var i = 0; i < values.length; i++) {
        str += "L " + Math.round((i+1) * SPARK_INTERVAL) + " " + Math.round(-values[i] * SPARK_INTERVAL);
      }
      return str;
    };

    // determine y offset
    function makeAlignmentFromValues(values) {
      var min = Infinity;
      for (var i = 0; i < values.length; i++) {
        min = Math.min(min, values[i]);
      }
      var y = (-min * SPARK_INTERVAL);
      if (min > 0) { y = -SPARK_STROKEWIDTH; }; // add the strokeWidth

      return new go.Spot(0, 1, 0, -y);
    }

    var sparkLine = $(go.Panel, "Horizontal",
      {
        alignment: go.Spot.Left,
        alignmentFocusName: 'spark'
      },
      new go.Binding('alignmentFocus', 'values', makeAlignmentFromValues),

      $(go.TextBlock,
        { visible: false, margin: 1, font: '11px sans-serif', background: 'white' },
        new go.Binding('alignment', 'values', function(values) {
          var min = Infinity;
          var max = -Infinity;
          for (var i = 0; i < values.length; i++) {
            min = Math.min(min, values[i]);
            max = Math.max(max, values[i]);
          }
          if (max - min === 0) return go.Spot.Center;
          return new go.Spot(0, 1 - Math.abs((values[0]-min) / (max - min)), 0, 0);
        }),
        new go.Binding('stroke', 'color'),
        new go.Binding('text', 'label'),
        new go.Binding('visible', 'label', function(l) { return true; })
      ),

      $(go.Shape, {
          fill: null,
          strokeWidth: SPARK_STROKEWIDTH,
          stroke: 'gray',
          name: 'spark'
        },
        new go.Binding('stroke', 'color'),
        new go.Binding('geometryString', 'values', makeStringFromValues)
      )

    ) // end sparkLine itemTemplate


    myDiagram.nodeTemplate =
      $(go.Node, "Auto",
        $(go.Shape, { fill: 'rgba(200,200,255,.3)', strokeWidth: 0 } ),
        $(go.Panel, "Spot",
          { itemTemplate: sparkLine },
          new go.Binding("itemArray", "items"),
          $(go.Shape, { width: 1, height: 200, fill: 'red', stroke: null, strokeWidth: 0 } )
        )
      );

    function rand(min, max) {
        return Math.random() * (max - min) + min;
    }

    // startValue optional
    function makeRandomValues(numberOfValues, /* optional! */ startValue) {
      var values = [];
      var last = startValue || rand(-30, 30);
      for (var i = 0; i < numberOfValues; i++) {
        var newval = last + rand(-3, 3);
        values.push (newval);
        last = newval;
      }
      return values;
    }

    myDiagram.model = new go.GraphLinksModel(
    [
      { key: "Alpha", items: [
          { color: '#FF69B4', values: makeRandomValues(50, 20) },
          { color: '#FFB6C1', values: makeRandomValues(50) },
          { color: '#FF69B4', values: makeRandomValues(50) },
          { color: '#C71585', values: makeRandomValues(50, -20) },
          { color: 'gray', values: [0] }
        ]
      },

      { key: "Beta", items: [
          { color: 'rgba(255,0,0,.6)', values: makeRandomValues(50), label: 'label A' },
          { color: 'rgba(0,0,255,.6)', values: makeRandomValues(50), label: 'long label B' },
          { color: 'darkgray', values: makeRandomValues(50), label: 'label C' },
          { color: 'lime', values: makeRandomValues(50), label: 'label D' },
          { color: 'gray', values: [0] }
        ]
      },

      { key: "Gamma", items: [
          { color: 'rgba(255,0,0,.6)', values: makeRandomValues(50, -10), label: 'Important\nYear' },
          { color: 'gray', values: makeRandomValues(20, 30) },
          { color: 'gray', values: makeRandomValues(40, 30) },
          { color: 'gray', values: makeRandomValues(50, 30) },
          { color: 'gray', values: [0] }
        ]
      }

    ],
    [ ]);
  }
</script>
</head>
<body onload="init()">
<div id="sample">
  <!-- The DIV for the Diagram needs an explicit size or else we won't see anything.
       This also adds a border to help see the edges of the viewport. -->
  <div id="myDiagramDiv" style="border: solid 1px black; width:700px; height:500px"></div>
  <p>
    This sample shows how to create and align sparkline style charts in a Node, using Spot Panel and <code>Panel.alignmentFocusName</code>.
  </p>
  <p>
    The Spot Panel's main element is a red vertical line, and its other elements are items in an item array. Instead of aligning to these item array items, which are Horizontal Panels, we want to align to the Shape that represents the sparkline, inside of the Panel.

    To do this we set <code>Panel.alignmentFocusName</code> to <code>"spark"</code>, and then set the <code>alignmentFocus</code> in
    <code>function makeAlignmentFromValues()</code> to the top left point, plus some offset to normalize the y-axis of the sparklines.
  </p>

  <p>
    The Sparklines exist in a horizontal panel with optional labels at the front, and these sparkline labels also have their alignment computed within the horizontal panel, based on the fractional height of the starting value of the sparkline.
  </p>

</div>
</body>
</html>